Strengthening by softening: Rigidity increase of a curved sheet from nonlinear regime of deformation

TL;DR

This paper reveals that the flexural strength of curved sheets can be increased through a softening of the clamp, due to geometry-induced rigidity, and shows that open curved sheets can resist bending better than closed cylinders.

Contribution

It uncovers a novel compliance effect where softening the clamp enhances rigidity in curved sheets, supported by experiments and numerical simulations.

Findings

Curved sheets exhibit increased flexural strength with softer clamping.

Open curved sheets can resist bending more than closed cylinders.

Geometry plays a key role in rigidity enhancement.

Abstract

It is well-known that a thin sheet held in a rigid circular clamp has a larger flexural strength than when it is flat. Here, we report that the flexural strength of curved sheets is further increased with a softening of the clamping condition. This unexpected compliance effect relates to the geometrical properties of curvature-induced rigidity that we observe in controlled experiments and further analyze with numerical simulations. In addition, we identify another compliance effect in which opened curved sheets can be more resistant to bending than closed cylinders of same dimensions.